I watched it a while ago, and I remember that I really liked the heroine's character design as the Ghost King. I don't remember any dissatisfaction with it.
When I grew up, I rarely read modern dramas. Many of the settings are too close to real life, and it is easy to feel suspended and awkward, which leads to drama. I recently read this book by chance and had a good experience. I especially praised it for its delicate emotional descriptions and good emotional tension.